The candidate is an anatomic pathologist with advanced training in surgical pathology and human breast and prostate diagnostic pathology;his research training is in cancer molecular biology and molecular pathology. He has studied mouse pathology in the context of genetically engineered mouse models of cancer for the past decade. He is a proven mentor in mouse pathobiology teaching medical and veterinary pathology residents and fellows, graduate degree, medical and veterinary students. He has served as teaching faculty in several national and international training courses. The plan for mentoring sponsored by this award includes: 1) Establishment of a funded training position for MD or DVM candidates with prior pathology training. 2) Development of an annual course on mouse specific pathology for the United States and Canadian Academy of Pathology Annual Meeting. And, 3) Establishment of a regular mouse cancer pathology telepathology conference using Whole Slide Image/ Zoomify Communications Tool technology. The research plan in mouse pathobiology research will build on funded work in the candidate's laboratory. The focus is on the use of genetically engineered mice to understand basic mechanisms of cancer. In particular, the laboratory has shown that isolation of experimentally defined mammary pre-cancer with heterogeneous histopathology reveals a "stem-like" behavior with pre-encoded cancer progression. The plan entails 1) Development of dissociation techniques and flow cytometry for isolation of specific cell subsets in mouse pre-cancers. 2) Characterize the histopathology of transplanted epithelial cells and 3) Isolate and define the progression events: a) pre-cancer to invasion and b) invasion to metastasis in the context of cell subset transplantation pathology. The environment is ideally suited to the objectives of this award. The UC Davis Center for Comparative Medicine and Mouse Biology Program has provided international leadership in the area of mouse pathobiology over the past decade. Relevance Statement: The genetically engineered mouse (GEM) has become the preeminent organism for modeling human disease. Understanding the pathobiology of the mouse is critical to the validity and success of this enterprise. Developing the national pool of expertise in the combined area of human disease, mouse biology and genetics is the primary objective of this proposal.